CAMELS AND LAMAS 285 tarsals are free, but with a tendency to fusion; the lateral toes are only represented at the upper extremity. The carpal bones are separated. This animal, which was about the size of a Sheep, though of more delicate proportions, was allied not only to the Tragu- lidae but to the Giraffidae; it is impossible to refer It definitely to either family. B. Fam. 5, Cameiidae.—This small group of Selenodonts in- cludes only the Camels and Lamas. The limbs are long and have no traces of the second and fifth toes. The fused xneta- earpals and metatarsals diverge somewhat at their distal ends. In the upper jaw is a single pair of incisors. The stomach differs from that of the typical Kurninants. The rumen has smooth and not papillose walls, and from it are developed the " water cells/* diverticula with narrow months provided with a closing sphincter muscle. The psaltexium is reduced to a mere vestige, and so the stomach has, as in the Tragulina, but three chambers. This, so far ancient, character in the structure of the Camel tribe is associated with another, also seen in the more primitive Ungulates, viz. the diffuse character of the placenta. A very singular peculiarity of this group is the fact that the blood corpuscles instead of showing the ordinary mammalian round contours are elliptical. The genus Oamelus, confined to the Old World, is made up of two quite distinct species, the Bactrian Camel, C. ftactrianus, with two humps, and the Dromedary, Cf. dromedarius, wifch only one. The former species is Asiatic. It is a singular fact that neither of the species is known to occur in a genuinely wild condition. The so-called " wild " Camels appear to be invariably feral. The two species will interbreed ; and there is at the Zoological Society's Gardens such a hybrid, which has the general appearance and shaggy brown hair1 of the Bactrian animal, but the one hump of the Dromedary. It may be that the Bactrian Camels of Lob-nor are really wild; but the desert contains so many remains of cities destroyed by sand-storms that these reputed wild 1 Tliis is the winter dress. In the summer both camels lose their long rough hair.